Hitherto, in the case of a sealing treatment of a small sized electric wire connected portion, in particular, a branched electric wire connected portion (e.g., a branched portion of a wire furnace of an automobile), it is known that an electric wire connected portion is covered with a composite sealing material wherein a viscous sealing piece is formed on one surface of a film with the viscous sealing piece being inside and pressing the sealing material by a press, whereby the viscous sealing piece is pressed into the portion to be sealed, such as an inner corner portion between the end of the coated layer on electric wires and a conductor connecting metal fittings as described in U.S. Pat. No. 4,863,535.
In this method, the composite sealing material covering the electric wire connected portion is pressed with a press in a state of covering the viscous sealing piece with the film.
However, since the viscous sealing piece of the composite sealing material is packed up in a small unit, the sealing work cannot be continuously carried out and it is difficult to employ automation for the sealing work. Also, a sealing piece has an intermediate property between a fluid and an elastic material, but in the above method, the property of the viscous sealing piece as a fluid is utilized for the compression of the viscous sealing piece. That is, a system wherein the fluid is contained in cells of the film and the fluid is pressed by reduction of the volume in the cell by compression is used. Accordingly, it is necessary to press the composite sealing material which covered an electric wire connected portion by folding the sealing material in a state of closing the end of the film. Thus, the force of pressing is increased, the pressing operation is complicated, and the sealing piece is extruded to cause a hindrance for the subsequent work.